EP3982415A1

EP3982415A1 - Display panel

Info

Publication number: EP3982415A1
Application number: EP20894904.0A
Authority: EP
Inventors: Mingxing LIU; Jingjing Zhao; Shizhen FENG; Wenxing Li; Weili Li; Shuaiyan GAN
Original assignee: Kunshan Govisionox Optoelectronics Co Ltd
Current assignee: Kunshan Govisionox Optoelectronics Co Ltd
Priority date: 2019-11-25
Filing date: 2020-07-28
Publication date: 2022-04-13
Also published as: EP3982415A4; US20220069253A1; JP2022538329A; WO2021103620A1; JP7299357B2; CN110752250A; KR20220002680A; CN110752250B

Abstract

Disclosed is a display panel defining a display area and a non-display area surrounding the display area, the display panel includes: a cathode lapping assembly, located in the non-display area of the display panel, the cathode lap assembly consists of an organic planarization layer, a seal layer, a cathode connecting wire and a cathode lead-out wire stacked sequentially, wherein the cathode lead-out line extends to the display area and connects with the cathode in the display area, the cathode connecting wire is configured to receive an external circuit signal and send the external circuit signal to the cathode lead-out wire, and the seal layer in configured to block water and oxygen in the organic planarization layer. Through the above method, the present application can reduce the corrosion of the cathode connection line by the water and oxygen in the organic planarization layer.

Description

TECHNICAL FIELD

The disclosure relates to display technology, and in particular to a display panel.

BACKGROUND

The display panel is generally defined with a display area and a non-display area located around the display area, a cathode of the display panel generally extends from the display area to the non-display area and is connected to a cathode lapping assembly in the non-display area. An external driving circuit can transmit electrical signals to the cathode through the cathode lapping assembly.
However, the wires in the cathode lapping assembly are susceptible to trace amounts of water and oxygen in the surrounding organic matter, which may affect the display quality.

SUMMARY

The main technical problem addressed in this application is to provide a display panel that can reduce the erosion of cathode connecting wire by water oxygen in an organic planarization layer.
To solve the above-mentioned problems, one technical solution of the present application is to provide a display panel defining a display area and a non-display area located surrounding the display area. The display panel includes: a cathode lapping assembly, located in the non-display area of the display panel, wherein the cathode lapping assembly includes an organic planarization layer, a seal layer, a cathode connecting wire and a cathode lead-out wire stacked sequentially; wherein the cathode lead-out wire extends to the display area and connects with a cathode in the display area, the cathode connecting wire is configured to receive an external circuit signal and send the external circuit signal to the cathode lead-out wire, and the seal layer is configured to block water and oxygen in the organic planarization layer.
The advantage of the present application is as follows: the display panel provided by the present application includes a cathode lapping assembly located in the non-display area, wherein the cathode lapping assembly includes an organic planarization layer, a seal layer, a cathode connecting wire and a cathode lead-out wire stacked sequentially, wherein the cathode lead-out wire extends to the display area and connects with the cathode in the display area, the cathode connecting wire is configured to receive an external circuit signal and send the external circuit signal to the cathode lead-out wire, and the seal layer is configured to block water and oxygen in the organic planarization layer. The above arrangement of the seal layer can protect the cathode connecting wire by preventing it from corroding by the water and oxygen in the organic planarization layer, so that the cathode lead-out wire and the cathode connecting wire can be effectively overlapped, and the lifespan of the display panel can be increased. And the design method of the seal layer is simple in process and easy to implement, which can make the cathode lead-out wire and the cathode connecting wire overlapped across the entire surface, and reduce the area occupied by the cathode lead-out wire and the cathode connecting wire, and facilitate the realization of a narrow frame.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic view illustrating the structure of a display panel in an embodiment of this application.
FIG. 2 is another schematic view illustrating the structure of a display panel in an embodiment of this application.
FIG. 3 is another schematic view illustrating the structure of a display panel in an embodiment of this application.

DETAILED DESCRIPTION OF THE EMBODIMENTS

A clear and complete description of the technical schemes in the embodiments of this application will be given below in combination with the drawings attached in the embodiments of this application. Obviously, the described embodiments are only a part of embodiments of the present application, not all embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.
Please refer to FIG. 1, FIG. 1 is a schematic view illustrating the structure of a display panel according to an embodiment of this application. The display panel 10 may be an OLED display panel, a Micro-LED display panel and so on. A display area AA and a non-display area CC surrounding the display area AA are defined in the display panel 10. The display panel 10 includes cathode lapping assembly 100, which locates in the non-display area CC of the display panel 10, and the cathode lapping assembly 100 includes an organic planarization layer 1000, a seal layer 1002, a cathode connecting wire1004 and a cathode lead-out wire 1006 stacked sequentially. The cathode lead-out wire 1006 extends to the display area AA and connects with the cathode 102 in the display area AA, the cathode connecting wire 1004 is configured to receive an external circuit signal and send the external circuit signal to the cathode lead-out wire 1006, and then further send the external circuit signal to the cathode 102; and the seal layer 1002 is configured to block water and oxygen in the organic planarization layer 1000.
In this embodiment, the seal layer 1002 is formed by one layer of silicon oxide, silicon nitride, aluminum oxide and graphene; or the seal layer 1002 is formed by at least two layers of silicon oxide, silicon nitride, aluminum oxide and graphene. The seal layer 1002 of the above-mentioned material is easy to obtain, and has a good water and oxygen blocking effect. The thickness of the seal layer can be 0.5 micron to 3 microns, such as 1 micron, 2microns and so on. The seal layer 1002 within this thickness range can not only satisfy the effect of blocking water and oxygen, but also does not increase the thickness of the frame of the display panel 10. When the material of the seal layer 1002 includes aluminum oxide, due to the high density of aluminum oxide material, its thickness can be in a relatively thin range, the thickness of the seal layer 1002 can be in a relatively thin range, for example, 0.5 micron to 1 micron (for example, 0.6 micron, 0.8 micron, etc.) due to the relatively high density of the aluminum oxide material.
The above arrangement of the seal layer 1002 can protect the cathode connecting wire 1004 by preventing it from corroding by the water and oxygen in the organic planarization layer 1000, so that the cathode lead-out wire 1006 and the cathode connecting wire 1004 can be effectively overlapped, and the lifespan of the display panel 10 can be increased. And the design method of the seal layer 1002 is simple in process and easy to implement, which can make the cathode lead-out wire 1006 and the cathode connecting wire 1004 overlapped across the entire surface, and reduce the area occupied by the cathode lead-out wire 1006 and the cathode connecting wire 1004, and facilitate the realization of a narrow frame.
In this embodiment, the organic planarization layer 1000 may further extended to the display area AA of the display panel 10, the side of the organic planarization layer 1000 far away from the cathode lead-out wire 1006 and cathode 102 may further include other structure. The organic planarization layer 1000 can reduce or minimize the problem of uneven surface of other structures caused by the process.
Otherwise, the material of the cathode lead-out wire 1006 can be the same as the cathode 102, which can be metal, for example, magnesium-silver alloy, etc. With this way of design, the cathode lead-out wire 1006 and the cathode 102 can be simultaneously formed (such as, simultaneously formed by evaporation), thereby simplifying the preparation process. In addition, the above-mentioned display panel 10 corresponding to the display area AA further includes an anode 104, the anode 104 and the cathode 102 are arranged interval and opposite to each other, and the anode 104 is relatively closer to the organic planarization layer 1000 than the cathode 102. A material of the anode 104 is the same as a material of the cathode connecting wire 1004, which can be indium tin oxide, etc. This design method can make the cathode connecting wire 1004 and the anode 104 be formed simultaneously, thereby simplifying the preparation process.
Further, the opposite and interval area between the anode 104 and cathode 102 in the display area AA of the display panel 10 may further include light-emitting layer 101, the light-emitting layer 101 can emit red light, green light, or blue light, etc. The outermost boundary of the light-emitting layer 101 can be regarded as the boundary between the display area AA and the non-display area CC.
Please continue to refer to FIG. 1. The cathode lapping assembly 100 may further includes a first organic limiting member 1008 and a second organic limiting member 1001 arranged at intervals. The first organic limiting member 1008 and the second organic limiting member 1001 are located in the organic planarization layer 1000, and the location of the first organic limiting member 1008 is relevantly closer to the display area AA of the display panel 10 than the second organic limiting member 1001. The seal layer 1002 and the cathode connecting wire 1004 are located in the interval area between the first organic limiting member 1008 and the second organic limiting member 1001, and the cathode lead-out wire 1006 covers the interval area between the first organic limiting member 1008 and the second organic limiting member 1001 and further covers the surface of the first organic limiting member 1008 to connect the cathode 102 located in the display area AA. The above-mentioned arrangement of the first organic limiting member 1008 and the second organic limiting member 1001 can better limit the positions of the sealing layer 1002 and the cathode connecting wire 1004, which is beneficial to control the frame width of the display panel 10. In addition, the first organic limiting member 1008 and the second organic limiting member 1001 are both in contact with the organic planarization layer 1000, so that the water and oxygen in the organic planarization layer 1000 can be spread and dispersed through the first organic limiting member 1008 and the second organic limiting member 1001. To further reduce water vapor, dry particles can also be set inside of the first organic limiting member 1008 and the second organic limiting member 1001.
Generally, the display area AA of the display panel 10 includes pixel defining layer 106 located on the organic planarization layer 1000 in the display area AA. The material of the pixel defining layer 106 is generally organic, the anode 104, the light-emitting layer 101 and the cathode 102 corresponding to each sub-pixel are arranged in the opening area between the pixel defining layers 106. A material of the first organic limiting member 1008, a material of the second organic limiting member 1001 and a material of the pixel defining layer 106 are the same, so that the first organic limiting member 1008, the second organic limiting member 1001 and the pixel defining layer 106 can be formed simultaneously during the preparation process, reducing the difficulty of the preparation process. Alternatively, the display panel 10 corresponding to the display area AA may further includes a spacer (not indicated) located at the side of the pixel defining layer 106 facing away from the organic planarization layer 1000. The material of the spacer is generally organic. The material of the first organic limiting member 1008 and the second organic limiting member 1001 can be the same as the material of the spacer, so that the first organic limiting member 1008, the second organic limiting member 1001 and the spacer can be simultaneously formed during the preparation process, reducing the difficulty of the preparation process. Still alternatively, the above mentioned first organic limiting member 1008 and second organic limiting member 1001 may be formed by stacking the pixel defining layer 106 and the spacer, which is not restricted in the disclosure.
Otherwise, in this embodiment, please continue to refer to FIG. 1. The side of the first organic limiting member 1008 far away from the organic planarization layer 10001 is contacted with the light-emitting layer 101 in the display area AA, that is, the first organic limiting member 1008 not only functions to limit the sealing layer 1002 and the cathode connecting wire 1004, but also functions to limit the light-emitting layer 101. The first organic limiting member 1008 may be located at the boundary line between the display area AA and the non-display area CC, thereby reducing the width of the non-display area CC of the display panel 10, which is beneficial to realize a narrow frame.
Further, please continue to refer to FIG. 1. The first organic limiting member 1008 includes a protruding portion 10080 exceeding from the cathode connecting wire 1004, and an angle α between a side wall (not indicated) of the protruding portion 10080 and a plane where the cathode connecting wire 1004 is located is greater than or equal to 90° and less than 180°, for example, the angle may be 120 degrees, 135 degrees, 150 degrees and so on. The design method of this included angle can reduce the probability of fracture of the cathode lead-out wire 1006 covering the first organic limiting member 1008.
In one embodiment, in a direction from the organic planarization layer 1000 to the cathode connecting wire 1004, a cross section of the first organic limiting member 1008 is of a regular trapezoid. This design method can reduce the probability of the cathode lead-out wire 1006 covering the first organic limiting member 1008 to be broken and can also reduce the complexity of the process of forming the first organic limiting member 1008. Further, as shown in FIG. 1, in the direction from the organic planarization layer 1000 to the cathode connecting wire 1004, a cross section of the second organic limiting member 1001 is of an inverted trapezoid. This design method can make the space between the first organic limiting member 1008 and the second organic limiting member 1001 larger, increase the coverage area of the cathode connecting wire 1004, and increase the overlapped area between the cathode lead-out wire 1006 and the cathode connecting wire 1004 and reduce the overlap resistance, so that the display quality of the display panel is improved.
Certainly, in another embodiment, in the direction from the organic planarization layer 1000 to the cathode connecting wire 1004, the first organic limiting member 1008 and the second organic limiting member 1001 may also have other structures. For example, the protruding portion 10080 of the first organic limiting member 1008 is a regular trapezoid, while the part below the convex may be a column, or other types of trapezoid, etc. For another example, the first organic limiting member 1008 and the second organic limiting member 1001 may be cylindrical, etc.
In another embodiment, please refer to FIG. 2, which is a schematic structural diagram of another embodiment of the display panel of the present application. the organic planarization layer 1000a located between the first organic limiting member 1008a and the second organic limiting member 1001a comprises a side surface facing to cathode connecting wire 1004a, the side surface is a continuous concave-convex surface (not indicated). The seal layer 1002a and the cathode connecting wire 1104a cover the concave-convex surface, and the seal layer 1002a and the cathode connecting wire 1004a form a structure with a continuous concave-convex shape. The patterned concave-convex shape can increase the overlap area between the cathode lead-out wire 1006a and the cathode connecting wire 1004a, reduce the overlap resistance, and improve the display quality of the display panel; and under the same conditions, this design method is conducive to reducing the frame width of the display panel 10a, that is, conducive to achieving a narrow frame.
In this embodiment, in a direction from the organic planarization layer 1000a to the cathode connecting wire 1004a, in FIG. 2, a section of a convex in the concave-convex structure of the organic planarization layer 1000a can shape as any one of square, rectangular, rhombus, and trapezoid etc. An orthographic projection of the concave-convex structure on a side of the organic planarization layer 1000a facing the cathode connecting wire 1004a may be a mesh or in other shape, while the mesh may be a cellular etc., and will not be limited by the present application.
Moreover, in FIG. 2, the height h of organic planarization layer corresponding to a convex surface of the concave-convex surface accounts for 20%-80% of an entire thickness of the organic planarization layer 1000a (such as, 30%, 50%, 70% etc.). On the premise that the concave-convex structure within this thickness range can increase the contact area between the cathode lead-out wire 1006a and the cathode connecting wire 1004a, the unpatterned area reserved under the concave-convex structure of the organic planarization layer 1000a will ensure its ability to cover the underlying structure with uneven surface like particles.
In another embodiment, please refer to FIG. 3, which is a schematic structural diagram of another embodiment of the display panel of the present application. The difference between the display panel 10c and the display panel 10 in FIG. 1 is that the seal layer 1002c may further covers at least part of a first surface of the first organic limiting member 1008c and at least part of a second surface of the second organic limiting member 1001c, the first surface of the first organic limiting member is disposed opposite the second surface of the second organic limiting member. This way of design can protect the cathode connecting wire 1004c from being corroded by the water and oxygen from the first organic limiting member 1008c and the second organic limiting member 1001c around it, so that the cathode lead-out wire 1006c and cathode connecting wire 1004c effectively lapped and the lifespan of the display panel 10c improved.
Referring back to FIG. 1, the display panel 10 provided by the present application will be further explained from the perspective of the preparation method.
A, providing a substrate, the substrate may be rigid or flexible, and there are display area AA and non-display area CC defined on the substrate.
B, forming a thin film transistor layer at one side of the substrate. The thin film transistor layer covers the display area AA, and the thin film transistor layer is used to drive the pixels in the display panel 10 to turn on or off.
C, forming an organic planarization layer 1000 on the side of the substrate with the thin film transistor layer on it. The organic planarization layer 1000 covers the thin film transistor layer located in the display area AA and covers the non-display area CC.
D, forming a patterned pixel defining layer 106 in the display area AA of the organic planarization layer 1000 on the side far away from the substrate, and forming a first organic limiting member 1008 and a second organic limiting member 1001 in the non-display area CC of the organic planarization layer on the side far away from the substrate. Among them, if the material of the pixel defining layer 106, the first organic limiting member 1008 and the second organic limiting member 1001 are the same, the pixel defining layer 106, the first organic limiting member 1008 and the second organic limiting member 1001 can be formed simultaneously.
E, forming a seal layer 1002 in the interval region between the first organic limiting member 1008 and the second organic limiting member 1001 using a chemical vapor deposition method.
F, forming a cathode connecting wire 1004 on the seal layer 1002, forming an anode in the opening of the pixel defining layer 106. When the material of the cathode connecting wire 1004 and the anode 104 are the same, the cathode connecting wire 1004 and the anode 104 can be formed simultaneously.
G, forming a light-emitting layer 101 on the anode 104.
H, forming a cathode lead-out wire 1006 on the cathode connecting wire 1004, forming a cathode 102 on the light-emitting layer 101. The cathode 102 is electrically connected with the cathode lead-out wire 1006; when a material of the cathode lead-out wire 1006 and a material of cathode 102 are the same, the cathode lead-out wire 1006 and the cathode 102 can be formed simultaneously.
When the structure of the display panel 10a is as the one shown in FIG. 2, before step E above, the preparation method of present application further includes: patterning the surface of the side of the organic planarization layer 1000a, which located between the first organic limiting member 1008a and the second organic limiting member 1001a, far away from the substrate, and forming a concave-convex structure on the surface of the organic planarization 1000a.
The above description is only the embodiments of the present application and does not limit the patent scope of the present application, any equivalent structure or equivalent process modification used according to the contents of the specification and accompanying drawings in the present application, no matter whether it is directly or indirectly used in any other related technical field, should be included within the protection scope of the present application.

Claims

A display panel defining a display area and a non-display area surrounding the display area, comprising:
a cathode lapping assembly, located in the non-display area of the display panel, wherein the cathode lapping assembly comprises an organic planarization layer, a seal layer, a cathode connecting wire and a cathode lead-out wire stacked sequentially,

wherein the cathode lead-out wire extends to the display area and connects with the cathode in the display area, the cathode connecting line is configured to receive an external circuit signal and send the external circuit signal to the cathode lead-out wire, and the seal layer is configured to block water and oxygen in the organic planarization layer.
The display panel of claim 1, wherein the cathode lapping assembly further comprises:
a first organic limiting member and a second organic limiting member located on the organic planarization layer and arranged at interval, wherein the first organic limiting member is relatively closer to the display area of the display panel than the second organic limiting member, and the seal layer and the cathode connecting wire are located in an interval area between the first organic limiting member and the second organic limiting member.
The display panel of claim 2, wherein the organic planarization layer extends to the display area of the display panel, the display panel corresponding to the display area comprises a pixel defining layer located at a side of the organic planarization layer, and a material of the first organic limiting member, a material of the second organic limiting member and a material of the pixel defining layer are the same.
The display panel of claim 2, wherein the organic planarization layer extends to the display area of the display panel, the display panel corresponding to the display area comprises a pixel defining layer located at a side of the organic planarization layer and a spacer located at a side of the pixel defining layer facing away from the organic planarization layer, and a material of the first organic limiting member, a material of the second organic limiting member and a material of the spacer are the same.
The display panel of claim 2, wherein the first organic limiting member comprises a protruding portion exceeding the cathode connecting wire, and an angle between a side wall of the protruding portion and a plane where the cathode connecting wire is located is greater than or equal to 90° and less than 180°.
The display panel of claim 5, wherein in a direction from the organic planarization layer to the cathode connecting wire, and a cross section of the first organic limiting member is a regular trapezoid.
The display panel of claim 6, wherein in a direction from the organic planarization layer to the cathode connecting wire, a cross section of the second organic limiting member is an inverted trapezoid.
The display panel of claim 2, wherein the organic planarization layer located between the first organic limiting member and the second organic limiting member comprises a side surface facing to the cathode connecting wire, the side surface is a continuous concave-convex surface, the seal layer and the cathode connecting wire cover the concave-convex surface, and the seal layer and the cathode form a structure with a continuous concave-convex shape.
The display panel of claim 8, wherein in a direction from the organic planarization layer to the cathode connecting wire, a cross section of a portion of the organic planarization layer corresponding to a convex surface of the concave-convex surface can be any one of square, rectangular, diamond, and trapezoid, and an orthographic projection of the concave-convex structure on the organic planarization layer is a mesh.
The display panel of claim 8, wherein a height of a portion of the organic planarization layer corresponding to a convex surface of the concave-convex surface accounts for 20%-80% of an entire thickness of the organic planarization layer.
The display panel of claim 2, wherein the seal layer further covers at least part of a first surface of the first organic limiting member and at least part of a second surface of the second organic limiting member, the first surface of the first organic limiting member is disposed opposite the second surface of the second organic limiting member.
The display panel of claim 1, wherein the seal layer is formed by one layer of silicon oxide, silicon nitride, aluminum oxide and graphene; or the seal layer is formed by at least two layers of silicon oxide, silicon nitride, aluminum oxide and graphene.
The display panel of claim 1, wherein a thickness of the seal layer is 0.5 micron to 3 microns.
The display panel of claim 13, wherein when a material of the seal layer comprises aluminum oxide, the thickness of the seal layer is 0.5 micron to 1 micron.
The display panel of claim 1, wherein the display panel corresponding to the display area further comprises an anode, and a material of the anode is the same as a material of cathode connecting wire.
The display panel of claim 1, wherein a material of a cathode lead-out wire is the same as a material of the cathode.